Assembling Engine

Feature Article from Hemmings Classic Car

As New York City's former mayor Ed Koch once said, "If you say you can't do it, then you are right, you can't." Even before hearing this truthful saying, I've always lived my life by those words. Whatever I have wanted to do, I did. Though sometimes the end results weren't always what I had expected they would turn out to be, I always felt good that, at least, I tried. Since buying my first car thirty-one years ago, and not knowing then how to gap a spark plug, through the years I've taught myself how to repair and restore old cars by maintaining a positive "can do" attitude.
So when I hear car owners say things like, "Oh, I would love to rebuild my car's engine myself, but I don't know how," I simply cringe. Well, by trying you will learn how. It's that simple. That's what I did many years ago, and now I'm able to rebuild engines today without giving the task a second thought. The most amazing part of rebuilding engines is that it's really quite simple to do. It's one of those things that, after you do it once, you're amazed at how easy it really was.
The way I look at it, a car is really nothing more than a life-size Monogram plastic model car kit that doesn't require a tube of glue to hold it together. The engine, well, that's just one Super Size bucket of bolts, with a bunch of nuts, washers, springs, gaskets, a bicycle chain and a few other specially designed parts thrown in for good measure. Yeah, there are some specifically engineered parts such as the crankshaft, pistons, connecting rods and camshaft included as well, but because these parts are designed in a specific shape, they will fit only one way. If you can get a crankshaft to fit where the camshaft goes, then consider yourself a genius.
There's a very simple formula to assembling an engine correctly without fear that it will explode in a grenade-like manner when the key is twisted, and that formula centers on the three C's: cleanliness, calculation and caution.
Cleanliness: Dirt is an engine's nemesis, and it is to be avoided at all cost. So your shop, workbench and tools must be Spic 'n Span clean and free of grease, and your clothes must be of the lint-free type to ensure no speck of dirt or fabric will get onto a bearing shell or clog up an oil galley during assembly. Use only clean, lint-free rags, and make sure the bagel and coffee are kept on the other side of the room. And don't even think about smoking, as even the tiniest piece of ash will ruin an engine.
Calculation: This is one of those times in life that you really wished you had listened to Mrs. Magillacutty when she tried to teach you how to divide, use fractions, and what decimal points actually mean. None of us wiseguys really thought we would ever need to know that stuff, but surprise! -- you do now. If you can't add, subtract or divide, rest assured that your engine is certain to explode or, with any luck, not start at all. Bearing clearances must be checked, piston rings must be gapped, crankshaft endplay must be confirmed and, most importantly, the camshaft must be properly degreed to ensure its design performs at its optimal best in relation to the crankshaft. To make matters worse, nearly all of these dimensions are calculated to the thousandth decimal. No amount of praying will guide you through this one, folks.
Caution: This is the simplest C of all to understand. In short, if the crankshaft won't spin around or the piston won't slide down, DON'T use a hammer. Repeat: DON'T use a hammer. Heed the caution that something ain't right within, and start over. Patience is needed in huge amounts when assembling an engine, and no amount of strong-arming a part into place will work. Perhaps the other C word that also applies is Careful.
Here's more teacher-like advice: Read books. And if you don't understand what you're reading, read it again. I've got several how-to engine building books in my library, and each and every book provided me with important, useful information. Even though I'm building a Pontiac V-8 at the moment, I just finished reading a book on building small-block Chevy engines and I learned some very helpful tips that I can apply to my Pontiac engine. Just read as much as you can, and sooner or later it will all sink in.
Another method I used to learn about engine building was to visit engine-building shops and watch how the pros assemble them. It doesn't matter if they're bolting together a straight-six and you're assembling a V-8, the same basic assembly techniques apply. And don't be afraid to ask questions. The more questions you ask, the more knowledge you will gain. Just don't ask too many questions or you'll find yourself face to face with the pavement outside. Capeesh?
But the absolute best way to learn how to assemble an engine is to take one apart. If you don't want to risk ruining your car's original matching-numbers engine, buy an engine from a salvage yard or from a fellow club member and test your skills on that. Set aside several hours so you don't have to rush, and have some paper on hand so you can take notes as you go along. Most importantly, lay out the parts in the same order as they were removed. Piston #2 needs to stay with connecting rod #2, and lifter #5 needs to stay with pushrod #5, etc. Use a permanent marker on each part to identify its number.
Most importantly, don't try to save money by using the cheapest machine shop. Machining the cylinders and crankshaft, cutting the valves and align-boring the crankshaft's main caps are the most critical parts of rebuilding an engine. Find out which shop is the best and pay the money. It will be worth it. And spend the extra money and have the crankshaft balanced, too; you'll be surprised how much smoother your engine will run.
The most rewarding part comes when it's time to start the engine. Like me, you might drop in the distributor 180-degrees out and the engine won't start, but mistakes are part of the learning curve. The only way to avoid making mistakes is not to try in the first place, and that's the biggest mistake of all.

This article originally appeared in the March, 2005 issue of Hemmings Classic Car.